Small bowel bacterial overgrowth following laparoscopic one-anastomosis gastric bypass: a prospective study based on small bowel aspiration and culture

Background Gastric resection for bariatric surgery is associated with nutrients deficiency, including thiamine and folic acid. Other sequelae of bypass surgeries have been described. The alteration in the anatomy and the motility pattern of the bowel may result in a blind bowel with subsequent small intestine bacterial overgrowth (SIBO). Aim The present study aimed to assess the prevalence of SIBO in patients undergoing one-anastomosis gastric bypass (OAGB) and the effect on thiamine and folic acid levels. Patients and methods The study included 40 patients planned for OAGB. Data on the prevalence of SIBO following OAGB and its implications on the nutritional status were collected. Results At the 6-month postoperative follow-up, the mean percentage of total weight loss was 27.61%. No statistically significant differences were found in the thiamine or folate levels as compared with the preoperative levels. A total of 20 (50%) patients had at least one GI disturbance symptom occurring at least once per week. Jejunal aspirate culture revealed SIBO in 31 (77.5%) patients. Comparing between patients according to the presence of SIBO revealed higher weight measures in patients who developed SIBO compared with those who did not. This difference reached the level of significance only in the preoperative and postoperative weight measures. There were no statistically significant differences in the percentage of total weight loss, the thiamine and folate levels, the other demographic data, or the gastrointestinal tract symptoms. Conclusion SIBO was highly prevalent after OAGB, with no apparent association with the thiamine or folate levels. The relationship between gastrointestinal tract symptoms and bacterial overgrowth was not statistically significant, with high incidence of asymptomatic SIBO. OAGB is an effective procedure for weight loss and resolution of comorbidities.